1,775 research outputs found

    An Improved Technique for Sectioning Hairs

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    An Improved Technique for Sectioning Hairs

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    Coastal oceanography and sedimentology in New Zealand, 1967-91.

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    This paper reviews research that has taken place on physical oceanography and sedimentology on New Zealand's estuaries and the inner shelf since c. 1967. It includes estuarine sedimentation, tidal inlets, beach morphodynamics, nearshore and inner shelf sedimentation, tides and coastal currents, numerical modelling, short-period waves, tsunamis, and storm surges. An extensive reference list covering both published and unpublished material is included. Formal teaching and research programmes dealing with coastal landforms and the processes that shape them were only introduced to New Zealand universities in 1964; the history of the New Zealand Journal of Marine and Freshwater Research parallels and chronicles the development of physical coastal science in New Zealand, most of which has been accomplished in last 25 years

    Development of a laser-induced heat flux technique for measurement of convective heat transfer coefficients in a supersonic flowfield

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    A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the load surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimental results agreed reasonably well with theoretical predictions of convective heat transfer of flat plate laminar boundary layers. The results indicate that this non-intrusive optical measurement technique has the potential to obtain high quality surface convective heat transfer measurements in high speed flowfields

    Mindfulness enhances episodic memory performance: Evidence from a multimethod investigation

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    Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training—episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance

    Experimental Demonstration of Time-Delay Interferometry for the Laser Interferometer Space Antenna

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    We report on the first demonstration of time-delay interferometry (TDI) for LISA, the Laser Interferometer Space Antenna. TDI was implemented in a laboratory experiment designed to mimic the noise couplings that will occur in LISA. TDI suppressed laser frequency noise by approximately 10^9 and clock phase noise by 6x10^4, recovering the intrinsic displacement noise floor of our laboratory test bed. This removal of laser frequency noise and clock phase noise in post-processing marks the first experimental validation of the LISA measurement scheme.Comment: 4 pages, 4 figures, to appear in Physical Review Letters end of May 201

    Childhood Sleep Problems, Response Inhibition, and Alcohol and Drug Outcomes in Adolescence and Young Adulthood

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    To our knowledge, no prospective studies examine the relationships among childhood sleep problems, adolescent executive functioning, and substance outcomes (i.e., substance use and substance-related problems). In this study, we examined whether childhood sleep problems predicted adolescent sleep problems and response inhibition. We also tested whether adolescent sleep problems and poor response inhibition mediated the relationship between childhood sleep problems and substance (alcohol and drug) outcomes in young adulthood.Study participants were 292 boys and 94 girls (M = 4.85, SD = 1.47) from a community sample of high-risk families and controls.When compared to their counterparts, those with trouble sleeping in childhood were twice as likely to have the same problem in adolescence. Childhood overtiredness predicted poor response inhibition in adolescence. Persistent trouble sleeping from childhood to adolescence and response inhibition in adolescence mediated the relationship between childhood sleep problems and drug outcomes in young adulthood, whereas overtiredness in childhood directly predicted alcohol use outcomes and alcohol-related problems in young adulthood.This is the first study showing a long-term relationship between childhood sleep measures and subsequent alcohol and drug outcomes. The developmental and clinical implications of these findings were discussed. Prevention and intervention programs may want to consider the role of sleep problems and response inhibition on substance use and abuse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79313/1/j.1530-0277.2010.01178.x.pd

    Sleep Problems in Early Childhood and Early Onset of Alcohol and Other Drug Use in Adolescence

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    Background : No prospective studies exist on the relationship between sleep problems early in life and subsequent alcohol use. Stimulated by the adult literature linking sleep problems to the subsequent onset of alcohol use disorders in some adults, we examined whether sleep problems in early childhood predicted the onset of alcohol and other drug use in adolescence and whether such a relationship was mediated by other known predictors of this relationship, namely, attention problems, anxiety/depression, and aggression in late childhood. Methods : This study is part of an ongoing longitudinal study of the development of risk for alcohol and other substance use disorders. Study participants were 257 boys from a community-recruited sample of high-risk families. Results : Mothers’ ratings of their children's sleep problems at ages 3 to 5 years significantly predicted an early onset of any use of alcohol, marijuana, and illicit drugs, as well as an early onset of occasional or regular use of cigarettes by age 12 to 14. Additionally, although sleep problems in early childhood also predicted attention problems and anxiety/depression in later childhood, these problems did not mediate the relationship between sleep problems and onset of alcohol and other drug use. Conclusions : This is, to our knowledge, the first study that prospectively examines the relationship between sleep problems and early onset of alcohol use, a marker of increased risk for later alcohol problems and alcohol use disorders. Moreover, early childhood sleep problems seem to be a robust marker for use of drugs other than alcohol. Implications for the prevention of early alcohol and other drug use are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65934/1/01.ALC.0000121651.75952.39.pd
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